Quiz 3 Flashcards
What is one example that shows how complex perception is?
Training computers that are accurate in identifying objects in our environment
Sensation
The transformation of information from external input into sensory representations
5 sensory organs
- Eyes
- Ears
- Mouth
- Touch
- Nose
Each organ translates a different type of
input
Transduction
Converting from natural state to neural signal/impulse
Perception
Transformation of information from sensation (sensory organ) to object recognition
Study of perception
The study of the transmissions of information from sensory input to object recognition
Steps of perception
- Distal stimulus
- Proximal stimulus
- Percept
- Mental representation
- Behavior
Distal stimulus
External input
Proximal stimulus
Sense organs
Percept
Experience (or perception)
Direct Perception by James Gibson
What you see is what you get
- Innate mechanisms forged by evolution
- No learning is required
Theory of Constructivism
Stimulus from environment is often ambiguous so to interpret it we need information from past experiences or knowledge to make inferences about what we perceive
Which theory argues that input is “incomplete”?
Theory of constructivism
Which theory argues that what we perceive is the reality?
Direct perception theory
Bottom-up
Information processing driven by stimulus data only
- Physical stimuli coming in
Is Theory of direct perception bottom-up, top-down, or both?
Bottom-up
Why is Theory of direct perception bottom-up?
Because it does not take into account prior knowledge or past experience, instead it simply takes what comes in and that is what we see.
- Stimulus driven
Top-down
Information processing driven by prior knowledge and expectations
Is Theory of Constructivism bottom-up, top-down, or both?
Both
Why is Theory of Constructivism both bottom-up and top-down?
Because it processes what is out there but we also need to interpret it with our past experiences
Examples that go against Gibson’s direct perception theory
- Poggendorf’s Illusion (which line continues?)
- White’s illusion (which grey is darker?)
- Zollner Illusion (are lines parallel?)
Lack of correspondence
When one’s mental representation (percept) does not correspond to the distal stimulus
Evidence for constructivism
- Lack of correspondence (we don’t see what is really there)
- Paradoxical correspondence (we see what is there)
Paradoxical correspondence
When the proximal stimulus DOES NOT correspond to the distal stimulus, BUT the mental representation (percept) DOES correspond to the distal
Example of paradoxical correspondence
When a car drives a way you don’t perceive it as shrinking even though it looks smaller, you perceive it as driving away
Paradoxical correspondence is evidence for constructivism because…
Because it shows that the brain uses prior knowledge and context to create perception
Why does lack of correspondence support constructivism?
It shows that perception can be inaccurate when sensory input alone is not sufficient - thus showing that interpretation and knowledge are important
Perceptual constancy
The tendency of animals and humans to see familiar objects as having standard shape, size, color, or location regardless of changes in the angle of perspective, distance or lighting
Perceptual constancies
- Color
- Shape
- Size
Perceptual constancy is when a mental representation of a distal stimulus remains…
constant even when the corresponding proximal stimulus change
Problems in transmission refers to…
Lack of correspondence
Corrections in transmission
Paradoxical correspondence
Problem of perception
The sensory information is incomplete
Sensory information is incomplete because…
- Too much sensory input (bottleneck theory)
- Inconsistent input
- Imperfect representation of input
Bottleneck theory
People have a limited amount of attentional resources that they can use at one time. Thus, the information and stimuli are filtered so only the most important is processed.
Perception depends on both … and … processes
bottom-up and top-down
Around what age do we learn depth cues
1st year
It is not until the child learns to move around on its own that it learns to use visual information from the environment to perceive…
depth
We receive … from our senses and we … for it using …
imperfect information
correct
experience and knowledge
Monocular cues (static)
Cues that can be used for depth perception that involve using only one eye.
- Allow us to convert 2D in our retina to 3D representation of our percept
List the monocular cues
- Linear perspective
- Texture
- Aerial perspective
- Relative size
- Interposition
- Shadows
- Accomodation
Linear perspective
Parallel lines appear to meet as they travel into the distance
Texture gradient
- The texture of an object becomes less and less apparent the farther it goes into the distance
- The shapes in foreground appear larger, and shapes in the background appear more compressed
Aerial perspective
The atmosphere diffuses light such that things closer to you are clearer than the things further away
Relative size
If two objects are roughly the same size, the object that looks the largest will be judged as being the closest to the observer
Interposition
When one object overlaps another, the object that is partially obscured is perceived as being farther away
Shadow
We assume that light is coming in from above
Accommodation
Near - lens is rounder
Far - lens flat
Binocular cues
- Retina disparity
- Convergence
Retinal (binocular) disparity
retinas (left and right) get different views of the same scene. The brain takes the difference to compute where things are in space
Convergence
The muscles that control your eyes - can be used to interpret
How do we construct perception
- Sensations
- Attention
- Experience
- Knowledge
- Current state
Prior experiences that change what we perceive
- preference for movement from left to right (reading)
- higher purchase intent based on handedness
Knowledge can change what you say you perceive
Knowing what is more expensive can change what you say you like
Mood affects perception
Height overestimation may be due, in part, to fear
Current state
- Mood
- Action or ability to act
- Need
- Bodily state
Action or ability to act affects perception
- Ex. if you are carrying heavy backpack you will perceive a hill as steeper because you feel less capable of climbing
- After shooting goal those who missed most goal was perceived as smaller
Need affects perception
Water more appealing when closer, less perceived distance
Bodily state affects perception
The way you are carrying your body influences perception (ex. smiling)
A Freudian psychologist gives a client the Rorschach Inkblot Test. The client views an abstract drawing and is asked what she sees. The client says, “ I see my mother and father fighting”. This is best explained by:
Constructivist theory
percept =/ distal
lack of correspondence
percept = distal =/ proximal
paradoxical correspondence
Bottomless bowl experiment
People wit bottomless bowl ate way more but thought they ate around the same as the other group (underestimated amount of food)
Sensory marketing
marketing designated to engage the costumers senses and affect their perception, judgement and behavior
Levers in sensory marketing
- Motion
- Sight
- Sound
- Aroma
- Design
- Texture
- Color
- Interactivity
- Touch
Sensory branding
Type of marketing that appeals to all the senses in relation to the brand
Sensory tactics are impacting…
- Awareness
- Recall
- Mood
- Need
- Preference
- Decision making
The power of smell - cleaning spray
Testing room with scented cleaning material vs unscented. Came up with more words and things to do related to cleaning. Cleaned up more after eating cookie.
The power of smell - wipes
Scented wipes more pleasant, stronger wipes, more effective and gentle and more purchase intention
The power of touch - coffee
Hot coffee - think the person who hands the coffee has warmer personality
The power of touch - pad
Hot pad more likely to give reward to friend
The power of touch: tactile warmth made people see metaphorical…
warmth in others and act in warmer ways
The power of music - wine
can increase sales of french wine by playing french music and german wines by playing german music
The power of sound - ice cream
- Front vowels: smaller and less powerful
- Back vowels: larger and more powerful
More wanted the frosh (back)
The power of touch - physical contact
small physical contact can increase likelihood to buy, try and buy a food
People prefer drinking wine from…
a more elongated glass
Example of senses not always working in the way you think it should - wine glass
Wine glass - elongated preferred but they feel less satisfied after
Example of senses not always working in the way you think it should - juice
Most difference in perception due to color difference (more than price and quality)
Why does sensory marketing not always work in the way we think it should?
Because sensation is not equal to perception
Popsicle case - marketing does not always work the way we think it should
Strawberry flavor
- Yellow popsicle too acidic
color flavors change our expectations and
change how we taste food
coffee in white mug tasted less sweet than in
transparent or blue mug
7up has a more lemon-limey taste when more yellow was
added to the packaging
strawberry mousse tasted better on a white round plate than
on a black square plate
Expectations bias sensory representations both
prior and during evidence accumulation
cross cultural differences affecting perception
- westerns focus on location based on right, left, up, down
Everyone experiences perceptual constancies and perceptual biases…
the same way
Interaction of color and
taste
Interaction of size and
color
Krishna experiment (car and heating pad)
Adding cinnamon to car (for funerals) and back heating pad - cinnamon makes people perceive heating pad works better but no difference on car
Superadditive IKEA
Scent and light (interaction) combination created a 50% increase in sales
Subadditive
Music + scent (interaction) combined decreased unplanned purchases
iPhone vs Nokia
Nokia (authentic brand) - congruent
Apple (exciting brand) - incongruent
What are the two things that determine perceived size?
- Size of proximal stimulus (retina representation)
- Depth cues to compute distance
The visual system must have both …. and …. in order to determine the true size of an object
- size of proximal stimulus
- depth cues to compute distance
Which best describes how depth can be determined based on binocular convergence
The amount of muscle movement required to turn the eyes inward/outward
The process of perception
- Color encoding
- Feature encoding
- Object encoding
- Object Recognition
What is the transmission of information in the visual system
- Light - retina
- Layer 1 - Layer 2 - Layer 3
- Layer 3 - Thalamus (LGN) - Visual cortex (V1)
- Visual cortex
- Parietal lobe
- Temporal lobe
How is information represented in this part of the visual system?
- Layer 1 (photoreceptors)
- Layer 3 (ganglion cells)
- Visual cortex
Transmission of information: light from distal to eye
- Light is emitted by light source
- Some frequencies of light are absorbed by a distal stimulus
- Other frequencies of light are reflected
- Some of this light reaches our eyes
Which is the area of the retina with highest concentration of cones?
Fovea
transmission: light from cornea to retina
- cornea
- pupil
- lens
- retina
What is the transmission of information in the visual system?
Light enters through the pupil into our eye and is refracted onto the retina on the back of the eye (light - cornea - pupil - lens - retina)
Transmission in retina
Layer 1: photoreceptors
Layer 2: bipolar
Layer 3: ganglion
From Layer 1 in the retina information is sent…
forward to layer 2 and 3 and then light goes back to retina and hits layer 1
Representation of information in the retina
the retina is basically a two dimensional sheet of on-off like buttons/cells
when the buttons/cells in the retina are active or inhibited they are…
ON
when the buttons/cells in the retina are in a resting state they are…
OFF
Visual field
The total area of space in which objects can be ‘detected and processed’
Our visual field includes both what is captured in our
central and peripheral vision
Visual receptive field:
a region of the visual field that is “processed by” a single neuron in the retina
In the visual receptive field, the presence of a stimulus will alter…
the firing of one specific neuron
Hubel and Wiesel - mapping the receptive field
Simple cells respond to what
Complex cells respond to where
How do receptive fields in the retina contribute to the processing of visual information?
They break down visual stimuli into elementary features, such as edges and orientation.
In which layer of the retina is light converted into neural signals, and the features of visual information are coded by cells?
Photoreceptor Layer
Feature detection (decomposition)
Color
- Cones
Form
- High spatial resolution
- Low temporal resolution
Motion
- Low spatial resolution
- High temporal resolution
What layer of the retina are rods and cones located in?
Layer 1 - Photoreceptor layer
What layer of the retina is center-surround organization in?
Layer 3 - Ganglion
Hubel and Wiesel
Cats - visual receptive field and visual field
Cones
- Color
- Fovea
- 3 types - B, G, R
Cones: Their primary role is to enable us to see … … and to detect … … , especially in well-lit conditions.
- in color
- fine detail
Cones are the … and rods are the …
- WHAT
- WHERE
Cones work alongside rods, which are photoreceptors responsible for vision in … …. and are more sensitive to …. .
- low light
- movement
Rods
- Black and white - brightness
- Periphery
Photoreceptors
Traduce light energy into neural signal
Which of the two (rods or cones), is located in the center of the retina (fovea)?
Cones
Which of the two (rods or cones), is good for movement?
Rods
Which of the two (rods or cones), has high sensitivity and low acuity?
Rods
In feature detection which one of the following represents the WHAT?
a. Form
b. Motion
c. Color
A
Compiling (abstraction) in the retina
Information gets put together and compiled to come up with an image
Transmission involves the …
compilation of information from most basic to increasingly complex and abstracted representations
In layer 1, light is converted into…
neural signal and the feature of the visual information in the environment are coded by the rods/cones in this layer of the retina
In the layer 3 of the retina (ganglion cells), there are … types of … …
- 2
- receptive fields
On-center/off-surround and off-center/on-surround is in the …
ganglion cells
Information representation in the ganglion cells occurs through…
Center surround organization
What are the two types of receptive fields in ganglion cells?
- On center, off surround
- Off center, on surround
How is information coded in the ganglion cells?
Point detection
- Complimentary layering creating an overlap between the on-center and the off-center
Contiguous cells have … receptive fields
contiguous
Ganglion cells - White
large response by On-center
Ganglion cells - Black
large response by Off- center
Information consolidation
Lower layers of cells feed to higher layers and information gets condensed/compiled in this transmission process
Transfromation: visual cortex (V1)
Simple, complex, hypercomplex
Transmission: light - occipital cortex
- Rods and cones
- Bipolar cells
- Ganglion cells
- Lateral Geniculate (LGN)
- Occipital lobe
Occipital lobe and occipital cortex
they are in the same area
How is information coded in the visual cortex?
3 types of cells: simple, complex and hypercomplex
Simple cell
- Dot to lines
- Input from LGN
- Bar of light
- Specific orientation
- Specific retinal position (visual space)
Complex cell
- Input from simple cells
- Bars of light anywhere
- Absolute position does not matter
- Some respond well to movement
- Edge detection
Hypercomplex cell
- Input from complex
- Specific sizes of bars of light
- Some respond well to angles, corners and gaps
How is information presented in this part of the visual system? (visual cortex)
Retina & LGN
- Position
Simple cells
- Bars & orientation
Complex cells
- Movement
- Edges
Hypercomplex
- Angles
- Corners
Parvo
Patterns/color/form
- Sustained response
- Small receptive field
WHAT
Magno
Movement/Location
- Transient response
- Larger receptive field
WHERE
Information differentiation
- Light
- Rods and cones
- Bipolar cells
- Ganglion cells
- M cells
- P cells
The P cells of the retina are most likely to receive information from which type of cells?
A. Hypercomplex
B. Rods
C. Simple cortical cells
D. Cones
D. Cones
M and P cells are … in the …
- Ganglion
- Retina
Magno and Parvo cells are cells in separate layers of the …
LGN
Kohler PET Study: Spatial vs Object
Spatial task: locations same or different?
Object task: objects same or different?
Results: parietal location, temporal object
Dorsal stream “where”
- Parietal lobe
- Magno cells
Ventral stream “what”
- Temporal lobe
- Parvo cells
The “what” is put together with the “where” by…
synchrony
The “what” is put together with the “where” by synchrony: when the … and … cells fire with the same ….
- dorsal
- ventral
- rhythm
Cortical specialization ventral face area
- Fusiform gyrus: face area
- Temporal lobe
Need … of activation across a population of cells to recognize objects
patterns
Pattern recognition
Must match the percept with the memory representation
Challenge for pattern recognition
- We identify objects we have never seen before
- We recognize objects from different angles, when partially obscured and when incomplete
Major challenge for pattern recognition
Shape constancy
Feature theory
Recognizing patterns by identifying its features
- Percept and memory = lists of features
Pandenomium model of Feature theory
- Image demon
- Feature demons
- Cognitive demons
- Decision demon
Evidence for feature theory
- Physiology (recordings from neurons)
- Stabilized retinal images (things fade away if u dont blink)
- Caricatures
Stabilized retinal images
- Circle goes away
- BEER missing letters
Evidence againts feature theory
- Relationship among features matters (different arrangements of the same features produces different objects)
- Natural objects (ex. the faces of people are hard to classify into features)
Feature theory is a … theory
bottom-up
Recognition-by-components theory is an example of a
structural theory
Recognition-by-components main idea
we decompose an object into basic components, or primitives, which are called geons. Each representation is a list of the geons in the object and the relationship among the geons.
What are geons?
They are a basic alphabet:primitive unit of analysis
- 3 dimensional shapes
- 100 different relations
the RBC theory addresses the main limitations of feature theory because…
it includes the relationships between the different objects
4 steps to matching in RBC theory
- Detect elementary features
- Find non-accidental properties
- Determine component geons
- Match geons to memory
Non-accidental properties
Do not change from view to view (ex. square will always have the same amount of angles no matter how you look at it)
Evidence for structural theory
- Partial or degraded objects
- Object complexity
- Unusual orientations
- Physiological evidence (monkey experiment)
Biederman monkey experiment
Supports RBC
- Showed different objects to identify neuron that responds only to objects sharing certain geons
Evidence against RBC theory
- More brain evidence needed
- Difficulty distinguishing similar objects
- Can’t explain context effects (somethings is harder to recognize when it is out of place)
Bottom-up theories
- Feature theory
- RBC theory
Top-down processing: 2 types
- Expectation/bias (beer study)
- Context (ex. ambiguous letters and the cat)
Agnosia
inability to interpret sensations and hence to recognize things, typically as a result of brain damage.
Akinetopsia
“motion blindness”, which is a higher visual processing disorder from an extra-striate lesion, in which a patient has difficulty specifically perceiving objects in motion with variable severity and rarely complete.
Embodied cognition
Without our conscious awareness, our bodily sensations help determine the decisions we make
Example of embodied cognition
- Warm beverage - person more friendly
Perception can involve a process similar to …
reasoning or problem solving
Perception occurs in conjunction with…
action
Difficulties involved in designing a “perceiving machine”
- The stimulus on the receptors is ambiguous
- Objects can be hidden or blurred
- Objects look different from different viewpoints
What is the inverse projection problem?
A task of determining the object responsible for a particular image on the retina
Do humans struggle with inverse projection problem?
No, computers do
Viewpoint invariance
The ability to recognize an object seen from different viewpoints
Bottom-up processing starts at the beginning of the system, when environmental energy…
stimulates the receptors
Bottom-up examples: Perceiving objects and people
- ASK or 456
- Rice et al and Calbi et al
Rice et al (2013) - identifying people
When facial features were ambiguous, participants used information from the body
- Participants were not aware that they were looking at body features, they thought they were looking at the faces
Calbi et al - emotional expressions
The dynamic emotional context of short video fragments affected how participants rated the emotional expression of a neutral face
- Ex. in fear context neutral faces more negative
Bottom-up examples: Hearing words in a sentence
If you speak the language - speech segmentation, if you do not unbroken string of sound
Speech segmentation
Being able to tend where one word ends and the next one begins
Bottom-up examples: Experiencing pain
- Hospital study, placebo study and gaming study
Hospital study
Surgical patients were told what to expect and were told to relax to alleviate pain. Patients requested less painkillers after surgery and were sent home earlier.
Placebo studies - Finniss et al
Significant proportion of patients with pathological pain get real relief from taking placebo
Nilsson study - gaming
Gaming can help reduce pain behavior and subjective distress in children undergoing wound care
Helmholtz’s theory of unconscious inference
- Said that image on the retina is ambiguous
- Likelihood principle
- Unconscious ineference
Likelihood principle
We perceive the object that is most likely to have caused the pattern of stimuli we have received
Unconscious inference
Our perceptions are the result of unconscious assumptions, or inferences, that we make about the enviornment
The Gestalt principles of organization
- The whole is more than the sum of its parts
Visual perception is based on more than just the pattern of light and dark on the retina
Principles of perceptual organization (Gestalt)
- Principle of good continuation
- Pragnanz
- Similarity
Principle of good continuation
- Points that, when connected, result in
straight or smoothly curving lines are seen as belonging together, and the lines tend to be seen as to follow the smoothest path. - Objects that are overlapped by other objects are perceived as continuing behind the overlapping object
Principle of pragnanz (or good figure/simplicity)
the perceptual field
and objects within it will take on the simplest and most encompassing (ausgezeichnet) structure
permitted by the given conditions
Similarity principle
Similar things appear to be grouped together
- Size, shape, orientation, enclosure or proximity
Regularities of the environment
Characteristics of the environment that occur frequently and therefore strongly influence what we expect to see
Two types of regularities
- physical regularities
- semantic regularities
Physical regularities
Regularly occurring physical properties of the environment
- Ex. there are more vertical and horizontal orientations in the environment than oblique
- Ex. light from above
Oblique effect
People can perceive horizontals and verticals more easily than other orientations
Semantic regularities
The characteristics associated with the functions carried out in different types of scenes.
Ex. airport: check-in, security, boarding…
Scene schema
Knowledge of what a given scene typically contains
Palmer - scene schema study
Presented a context scene such as a kitchen and then participants were asked to identify the object in the target picture like a loaf of bread.
- They identified the object more easily when the object fit the scene
Bayesian inference
Our estimate of the probability of an outcome is determined by two factors:
1. Prior: The prior probability or simply the prior
2. Likelihood:The extent to which the available evidence is consistent with the outcome
Prior probability or prior
Our initial belief about the probability of an outcome
Radel and Clement-Guillotin study on role of motivation
Whether being hungry or not affected how quickly and how accurately food-related words are seen.
Food related words easier and better perceived by the hungry people.
Nasr and Tootell - horizontal and vertical study humans
the PPA shows higher fMRI activity when things are presented in vertical and horizontal ways. More neurons respond to horizontals and verticals..
Why are there more neurons that respond to horizontal and verticals?
- Theory of natural selection - Darwin
The mechanism through which the structure of the brain is changed by experience is…
experience-dependent plasticity
Blakemore and Cooper - cat shaping by experience
Cats that had been put in an environment with horizontal lines recognized those and ignored vertical after, and same the other way around
Gauthier et al study of experience-dependent plasticity - faces
Learned Greeble faces and the fusiform face area (FFA) eventually learned to recognize them in the same way as faces
Brain lesioning
The study of the effect of removing parts of the brain in animals
Neuropsychology
the study of the behavior of people with brain damage
Ungerleider and Mishkin - monkey
Removed a part of the monkey’s brain which affected its ability to identify an object and where it is.
Temporal lobe - WHAT
Parietal lobe - WHERE (discrimination problem)
What pathway
The pathway leading from the striate cortex to the temporal lobe
Where cortex
Pathway leading from the striate cortex to the parietal lobe
Visual agnosia
No longer could recognizing everyday objects, familiar faces and geometrical shapes, despite being
able to identify an object’s colour or visual texture. DAMAGE TO VENTRAL
Inverse projection
Occurs because a huge number of possible objects could be associated with a particular image on the retina
which type of cell does not take in info from the env
hypercomplex
P cells are
SUSTAINED RESPONSE (long continuous firing)
M cells are
TRANSIENT (short bursts)
